Blank feeding means for folding apparatus and the like



E. W. CLEM July 2, 196s BLANK FEEDING MEANS FOR FOLDING APPARATUS ANDTHE LIKE July 2 E. wc| EM 3,390,876

BLANK FBEDING MEANS FOR FOLDING APPARATUS AND THE LIKE med Feb. 25,`1966 5 sheets-sheet 2 INVENTOR. EVERETT W. CLEM ATTORNEYS E. w. CLL-:M3,390,876

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E. W. CLEM July Z, 1968 BLANK FEEDING' MEANS F'R FOLDING APPARATUS ANDA'.IHE LIKE 5 Sheets-Sheet 5 Filed Feb. 25, 1966 FIG.6

INVENTOR. EVERETT W. CLE M ATTORNEY United States Patent 3,390,876 BLANKFEEDING MEANS FOR FOLDING APPARATUS AND THE LIKE Everett W. Clem,Shrewsbury, Mass., assignor to Specialty Equipment Corporation,Westboro, Mass., a corporation of Massachusetts Filed Feb. 25, 1966,Ser. No. 530,106 11 Claims. (Cl. 271-32) ABSTRACT F THE DISCLOSURE Thisinvention is concerned with an apparatus for precisely and flexiblyhandling corrugated carton blanks often of asymmetrical configuration,and typically supplying them to a folder-taper or folder-gluer machine.The speciication discloses a novel vacuum conveyor system incorporatingmobile suction boxes having a significantly smaller suction area thanthe area of the suction belt available to convey the carton blanks. Thesuction boxes may also include movable valve plates for providingadditional fiexibility to the adjustable suction boxes. An auxiliaryfeed roll for imparting a forward impetus to Va blank, :at the bottom ofa vertical stack as well as a pull roller assembly for supplying theblanks from the vacuum conveyor to the folding machine are alsodisclosed.

The present invention is ydirected to facilities for feeding blanks forcorrugated board cartons, and is directed specifically to improvementsin feed table :arrangements for feeding the lowermost corrugated boardblank from a stack of such blanks, and 4advancing the blank reliably andaccurately into a processing apparatus, such as a folder-gluer orfolder-taper, for example.

In the manufacture of shipping cartons formed of corrugated board, it isoften desirable to feed the blanks, one at a time, into a folderapparatus or the like, whic-h advances the corrugated board blanklongitudinally, while performing a series of manipulative operationsthereon, such as scoring, gluing, folding, securing, etc., the generalsequence of operations being well known. In the handling of thecorrugated blank, it is important to maintain accurate alignment andsquareness, lso that the various folding and closing operations areproperly performed and the discharged product, in the form of a flattube, usually secured by glue or tape, is properly squared and aligned.This sometimes proves to be rather difiicult, in connection withcorrugated board blanks, partly because of an inherent tendency of theblanks to assume a bowed or curved configuration in storage and, ofperhaps greater importance, because of an increasing tendency to packagegoods in corrugated containers of :a somewhat complex nature, involvinghighly asymmetrical, die-cut blanks. The facilities of the presentinvention are aimed particularly at the handling of bowed and/or highlyasymmetrical blanks with precision and accuracy, although it will beunderstood that the facilities will be equally applicable to moreconventional, generally rectangular blanks.

In accordance with one of the general objectives of the invention, animproved vacuum feed table means is provided for a folder-gluer,folder-taper machine or the like, which is adapted in a highlyeffective, precise, and controlled manner, to feed corrugated blanks ofVarious sizes, shapes, and configurations on a one-at-a-time basis fromthe bottom lof Ia stack of such blanks. Heretofore, for this generalpurpose, it has been proposed to utilize vacuum-actuated feed beltmeans, and the present invention contemplates the use of suchvacuum-actuated feed belt means but incorporates therein improvements ofa significant nature,gresulting in a substantial improvement in theability of the feed table system to advance 3,390,376 Patented July 2,1968 FPice asymmetrical blanks under control and precise alignment and,at the same time, improving the overall eiciency of the equipment.

More specifically, the `apparatus of the invention includes avacuum-actuated feed table facility in which a perforated conveyor beltmeans (advantageously comprising a plurality of belts) is advanced in agenerally horizont-al traverse over Suction chamber means arranged tolie adjacent the leading edge area of the lowermost corrugated cartonblank of a stack thereof. Conventionally, the perforated belt has awidth suitable to accommodate a blank of the maximum width capable ofbeing handled by the feed table and the folding lapparatus.Uncharacteristically, however, and in accordance with one aspect of t-heinvention, the suction chamber means advantageously has a capacity whichis greatly less than the maximum width capacity -of the machine(typically half or less) and is comprised of a plurality yofindependently transversely movable suction boxes. In accordance with theinvention, the independently Vadjustable suction boxes may bemanipulated to lie under are-as of the blank where maximum vacuumeffectiveness is desired, and, in a like vein, removed from areas where,by reason of a die-cut recess, for example, the presence of a suctionbox would be useless, yor at least wasteful of the s-uction effort, andpossibly even detriment-al.

In accordance with another specific aspect of the invention, suction boxfacilities are provided, advantageously of the type and having thecharacteristics mentioned in the preceding paragraph, which are providedwith `a plurality of transversely spaced, longitudinally elongatedvacuum openings, each controlled by a sliding door or similar valvedevice, enabling the several suction openings of each suction box to beselectively opened and closed or partially opened land closed. Byvariably adjusting the length of the individual suction openings, onecan optimize the suction effort, and avoid undue leakage at the back ofthe openings when handling severely bowed blanks.

As will be made apparent, the precise and highly ilexible suctioncontrol afforded by the apparatus of the invention enables unusuallyconfigured blanks to be handled with extraordinary effectiveness, whichis most important, and with minimized power utilization and equipmentwear, which is a secondary although significant consideration.

In accordance with -another specific aspect of the invention, animproved vacuum feed table is provided for corrugated carton blankswhich includes a longitudinally Iadjustable transversely disposedauxiliary feed roller element arranged to engage and support the rearedge extremity of a blank Waiting to be advanced by the feed tablefacility, the 'arrangement being particularly characterized by theprovision of a novel and improved, tiltingly adjustable support for theauxiliary feed roller element, enabling it to be raised and lowered asnecessary to accommodate various amounts of bowing or larcing which maybe present in the corrugated blanks supplied to the feed table. Theimproved adjustable facility enables the a-uxiliary'feed roller to belocated in its most effective position quickly and precisely, so thatchange-over time for converting the feed table to handle a new size andshape of blank is greatly minimized.

In accordance with another significant aspect of the invention, noveland improved pull-out roller means are provided in conjunction with thefeed table or other facility supplying corrugated blanks, whichprecisely grip and advance successive' corrugated blanks and maintainthem in accurate alignment, as desired. In this respect, it will beunderstood that the pull roller facilities of the yapparatus must have alength suitable to accommodate a blank of maximum width yet frequentlywill be called upon to handle blanks of only a fraction of that width,which may or may not be precisely centered with respect to the ends ofthe pull rollers and may or may not be of symmetrical configuration.Heretofore, this has resulted in significant diflicuties in maintainingproper alignment during the passage of the blank through the pull-outrollers. In accordance with the present invention, duplicate,resiliently covered pull-out rollers are provided, which are adjustablymounted to accommodate corrugated carton blanks of the variousconventional flute thicknesses. The new adjustment facilities include astepped abutment gauge at each end, for precisely and rigidly settingthe pull-out gap and eliminating from the adjusting system all effectsof thread and gear backlash, etc., which, even though of only a fewthousandths of an inch in magnitude, is sufficient to tilt theadjustable roll and throw a blank out of desired alignment.

Advantageously, the pull-out roller arrangement, as described above,includes rubber-covered pull-out rollers, the rubber surfaces of whichare annularly grooved at closely spaced intervals across their workingwidths. When the pull-out rollers are properly adjusted for a givenflute height of corrugated board, the actual roll gap is somewhatnarrower than the actual thickness of the corrugated board, in order toprovide for adequate gripping, and the provision of annular groovesenables the rubber surfacing material to be distorted or displacedlaterally into the groove areas. This minimizes circumferentialdistortion and displacement and thus further enhances the accuracy ofcontrol over the blank as it passes through the pull-out rollers.

For a better understanding of the above and other features andadvantages of the invention, reference should be made to the followingdetailed description and to the accompanying drawing, in which:

FIG. 1 is a side elevational view of a feed table apparatusincorporating the various features of the invention;

FIG. 2 is a fragmentary cross-sectional view, as taken generally alongline 2-2 of FIG. 1;

FIG. 3 is an enlarged, fragmentary view, similar to FIG. 1, showingdetails of a suction box adjustment facility and of the pull-outadjustment facility;

FIG. 4 is an enlarged, fragmentary, cross-sectional view, as takengenerally along line 4 4 of FIG. 3;

FIG. 5 is an enlarged, fragmentary, cross-sectional view, as takengenerally along line 5-5 of FIG. 4; and

FIG. `6 is a top plan view of a suction box assembly incorporating theprinciples of the invention.

Referring now to the drawings, and initially to FIG. 1 thereof, thereference numeral 10 designates generally a frame structure for thevacuum feed table arrangement of the invention, which is arranged to bepositioned adjacent, or to form an integrated part of, a corrugatedblank processing facility, such as a folder-gluer or foldertaper, forexample. A typical apparatus for this purpose is illustrated in theEverett W. Clem U.S. application Ser. No. 224,951, tiled Sept. 20, 1962,and/or in the Everett W. Clem U.S. application Ser. No. 523,347, filedon Ian. 27, 1966.

In the apparatus illustrated in FIG. 1, the frame structure 10 supportsa plurality of rollers 11, 12, 13 arranged in a generally triangularconfiguration and training a perforated suction belt 14 advantageouslyconsisting of several (eg, three) side-by-side belt sections. Therollers 12, 13 are so arranged that the belt has a generally horizontalupper traverse, and one of the belt rollers 11 is driven to impart aforward (left to right) motion to the perforated belt on its uppertraverse. Between the upper belt rollers 12, 13 there may be provided anappropriate plurality of idler rolls 15, which support the perforatedsuction belt 14 along its horizontal, forward traverse. The roller 12 isdivided into three roller sections, each arranged for cooperation withone of the belt sections. The separate roller sections are independentlyadjustable, longitudinally of the table axis, for initial tensionadjustment of the separate belt sections. A tension control idler 15a,mounted on a pivot arm 15b and adjusted by a screw 15C, may be providedfor simultaneous tension adjustment of all belt sections subsequent tosetting of the roller sections 12.

Spaced well above the forward portion of the suction belt 14 is atransverse bar 16, which slidably supports a plurality of guide arms 17.The outermost of the guide arms 17 support guide plates 18, which aredisposed in a vertical plane, aligned with the centerline of the machineand extend to a point closely above the upper traverse of the suctionbelt 14. The guide plates 18 extend from forward abutment plates 19,arranged to engage the front edges of a plurality of corrugated cartonblanks 20 arranged in a vertical stack. Actually, as illustrated, it isdesirable and intended that the vertical stack will be tilted backwardslightly from bottom to top, by the slight offsetting of each blankrelative to each adjacent blank, to facilitate the one-at-a-time feedingof the lowermost blank olf the stack, in rapid sequence.

As will be understood, an opposed pair of corner guides, each comprisinga side guide plate 18 and a front edge abutment 19, can be adjusted toguide and confine the front corner regions of a stack of corrugatedcarton blanks, at least where the blanks are of generally rectangularconguration. In conjunction therewith, and in some cases alternativethereto, it is usually desirable to provide one or more intermediateguides in the form of blades 21 arranged to be received in cut-out slots22 (see FIG. 2) in the carton blanks 20. As will be understood, wherethe corrugated blanks are of unusual or asymmetrical configuration, itmay be impractical to use the corner guides 18, 19 effectively, in whichcase the stack of blanks is guided and aligned entirely by one or moreof the guide blades 21.

As shown in FIG. 1, the guide elements are provided with an adjustmentfacility 23 permitting their lower edges to be raised and loweredrelative to the top surface of the suction belt 14. The arrangement issuch as to provide for a gap adjustment above the suction belt,accommodating the passage of a single corrugated blank of giventhickness but not more than one blank at a time.

In the illustrated apparatus, the various guide elements 18, 19, 21 aresupported along their lower edges by means of a transverse bar 24supported by the machine frame, which is arranged to engage and supportopensided bearing elements 25. The arrangement desirably is such thatany one of the guide elements may be slid or raised to an out-of-the-wayposition. The element may be secured in its out-of-the-way position orin its adjusted, in-use position by means Stich as a hand wheeltightener 26. Where odd shaped, die cut blanks are to be handled, one ormore of the guide elements may be padded out with blocks lfor properengagement with leading edge portions of the blanks.

Pivotally secured to the principal table frame 10 by means Iof pins orthe like are a pair of support -arms 31 which extend in a generallyrearward direction, typically from a point intermediate the uppertraverse of the suetion belt 14 to a point well to the rear thereof, thearms 31 being arranged in straddling relation to the suction belt, as'shown particularly in FIG. 2. Slidably guided in the support arms 31for movement longitudinally thereof is an auxiliary feeding carriage 32which rotatably supports. in its forward portions an auxiliary feedingroller 33, shown particularly in FIG. 2. The auxiliary feeding roller 33advantageously is provided with a knurled outer surface and may befreely journaled in the carriage 32 or lightly driven by means such as astalltorque motor.

As shown in FIG. l, the carriage 32 advantageously is adjustedlongitudinally of the support arms 3l, to a puirt such that thelowermost back edge extremity of the lowermost carton blank rests uponand is supported in an elevated position by the auxiliary roller 33,advantageously at a point near the forward extremity of the roller(e.g., 30 to 45 above a horizontal plane through its axis) such that thedownward force of the weight of the stack 34 of blanks tends to drivethe auxiliary roller 33 in a clockwise direction, simultaneouslyimparting a slight forward force component to the lowermost blank tobreak it free of the stack and start its forward advancing movementunder the primary influence Iof the suction belt 14 as will bedescribed. Usually, it -is adequate to simply freely journal thelauxiliary roller 33 Vand let it be actuated by the downward merging ofthe stack of blanks. However, it may be advantage-ous to drive theroller by means, such as a stall-torque motor, for example, such that apositive, external torque would be applied to the roller to make itsaction more effective.

As shown in FIG. 1, the auxiliary roller 33 is adjustably positionedlongitudinally along the support arms 31 by means of a pinion gear 34actuated by a hand wheel 35 carried by the carriage 32 and which mesheswith a rack 36 formed along the upper edge area of the support arm 31. Asimilar rack and pinion facility may be provided at the other side ofthe machine, for simultaneous manipulation by the hand wheel 35, as willbe understood. A-fter the carriage 32 has been advanced into a positionas illustrated in FIG. 1, it may be locked in such position by means oflone or more hand screws 37 at each side of the machine.

The typical proportions and location of the auxiliary feeding roll 33are such that, in the horizontal position of the supporting arms 31, asillustrated in FIG. 1, the auxiliary feeding roller 33 will properlyaccommodate corrugated carton blanks having a typical degree of bowingor arcing, substantially as illustrated. However, since the nature andextent of such :bowing or arcing is, to a large degree, lout of thecontrol of the processor and is linuenced by such factors as age,humidity, original manufacturing techniques, etc., occasional batches ofcarton blanks may be bowed to a much greater extent than the blanksillustrated in FIG. 1. To accommodate such greater degrees of bowing,the support arms 31 are pivotable upward about the pins 30, so that theauxiliary feeding roller 33, which serves to support the Iback edge ofthe lowermost blank, can be raised to a considerably greater heightabove the plane of the suction belt 14. The appropriate adjustmentfacility is provided by means of a hand crank 38 operating through aworm gear 39 to raise and lower a screw shaft 40 at each side of themachine. The adjusted, pivoted position of the support arm at each sidemay then be xed by means of hand screw tighteners As will be understood,the proper adjustment of the pivotable supporting arms 31 is such thatthe forwardmost leading edge area of the bottom blank lies substantiallyhorizontally lalong the upper traverse of the suction belt 14, so as tolbe effectively -gripped by suction applied through the belts.

Advantageously, the carri-age 32 carries one or more adjustable guideblades 42 arranged to be locked in la preset transverse location bymeans of a locking device 43 of suitable form, such that the blade 42 isreceived in a cut-out slot 44 in the back edge of the corrugated cartonblank. The 'blade 42, in conjunction with the corner guides or one ormore similar guide blades disposed at the front of the stack of blanks,serves to maintain precise alignment of the blanks with respect to thecenterline of the equipment, as will be understood.

In accordance with one of the particularly important yaspects of theinvention, novel and improved suction facilities are provided to actupon the upper, horizontal traverse of the suction belt 14 immediatelyadjacent the forward roller 13. While such suction arrangements are, ingeneral, known and'widely used, the provisions of the present inventionare such that suction is applied only to areas of limited transverseextent, the exact location and the overall extent of which is widelypreadjustable to accommodate in an optimum manner the specificconguration of the corrugated blank then being handled by the equipment.

In accordance with this aspect of the invention, the feed tableapparatus includes a plurality, mo-st advantageously four in a machineof conventional capacity, of individual suction -boxes 50, `arrangedacross the width of the machine but having a total effective widthconsiderably less (usually under half) of the maximum eifective vacuumwidth of the machine. Each of the suction boxes 50 is provided withange-s 51, 52 slidably received in supporting plates 53, 54 in themachine frame, whereby the suction boxes are freely slidabletransversely of the machine, in a horizontal plane below the uppertraverse of the suction belt. A pair of parallel, transversely disposedtubes 55, 516 passes in similar relation through the main chamber 57 ofeach of the suction boxes to accommodate the passage of threadedadjusting rods 58-61, there being a pair of threaded adju-sting rodsaccessible from each side of the machine, such that, in the illustratedapparatus, utilizing four independent suction boxes, there is aseparate, threaded adjusting rod for each independent suction box.

In the illustrated arrangement, the outboard suction box on therighthand side, shown in FIG. 4, is provided with a threaded bushing 62arranged for threaded engagement with the adjusting rod 58. The rod 58then passes through the corresponding tube 56 provided in the inboardright side suction box, without making engagement therewith, and theinner end of the -rod is then journaled in a frame bearing 63 in thecenter of the machine frame. The second threaded adjusting rod 59provided on the righthand side of the machine passes through the tube 55of the outboard box, without engagement, and is engaged by anappropriate threaded bushing 64 in the inboard box, and the rod 59 islikewise supported 'by the frame bearing 63. The arrangement is suchthat the inboard and the outboard suction boxe-s on the righthand sideof the machine may be independently adjusted transversely of the suctionbelt 14 by selective manipulation of the threaded adjusting rods 5? 59.In a similar manner, not requiring separate specie description, theinboard and outboard suction boxes on the lefthand side of the machineare separately and independently adjustable 'by appropriate manipulationof threaded adjustment rods 60, 61.

For the convenient and Iadvantageous adjustment of the threaded rods 58,59, each is provided with a pinion 65, 66 offset axially from the other.A drive gear 67, secured to a hand wheel 68, may be shifted axiallyalong a shaft I69, for driving engagement selectively with either one orthe other of the pinions 65, 66 (or the pinions may be shifted axially,if preferred).

In the illustrated apparatus, the overall transverse width of thesuction boxes 50 may be on the order of 1/3 the useful width of thevacuum belt 14, so that the combined vacuum box width is somewhere onthe order of 1/2 that of the vacuum belt. The actual available vacuumarea of the suction boxes may be somewhat less than this, say on theorder of 35% of the capacity of the machine. Accordingly, with blanks ofdifferent sizes, the individu-al suction boxes may be disposedtransversely underneath the suction belt 14 in an optimum manner,calculated t-o achieve reliable advancement of the bottommost blank of astack, without unnecessary wastage of suction capacity and withoutunneeded suction effectiveness, which serves merely to accelerate wearof the suction belt and other parts of the equipment, as well as toscuif and mark the blank, which may bear incompletely cured printinginks.

As shown in FIGS. 4-6, each of the suction boxes 50 has a front suctionchamber, communicating with a suction outlet 70 arranged to be connectedthrough a suitable exible yduct (not shown) to a suitable vacuum source(also not shown). The suction chamber, 57, advantageously extendsthroughout the entire width of the suction box and is provided with aplurality of longitudinally elongated inlet openings 71 along its topsurface. Typically, the openings 71, in conjunction, constitutesubstantially the entire upper surface of the suction chamber, beingseparated by relatively narrow longitudinal supports 72 and bounded atthe ends by relatively thin end wall sections 73.

In accordance lwith a specific aspect of the invention, each of thelongitudinally disposed openings 71 is provided with a longitudinallyadjustable closure plate 74, which is arranged for longitudinal movementfrom a first position in which the opening 71 is fully closed to asecond position in which the opening is entirely free of obstruction,being also capable of being set at any intermediate position topartially close olf the suction inlet opening. Advantageously, theclosure plates 74 have beveled edge areas 75 slidably received indovetail guide slots 76 adjacent the edges of the suction inlet openings71.

As shown in FIGS. 5 and 6, portions of the closure plates 74 extendrearward beyond the back wall of the suction chamber 57, overlying asupporting flange 79 which projects horizontally rearward from thesuction chamber. The supporting flange 79 is provided with a pluralityof vertical guide surfaces S3 Aforming guide grooves 85, in which areslidably received, guided, and supported a plurality of slide blocks 78secured to the projecting rear portions of the valve plates 74, as bymeans of screws 84. Suitable :bolts 81 extend through the slide blocks78 and engage nuts 82. The nuts 82 are arranged to bear against thebottom surface 86 of the supporting ange 79 and have upwardly projectingtongues or keys 87 received in elongated slots 88 formed in each of theguide grooves 85. The arrangement is such that the closure plates 74 maybe freely moved longitudinally from fully opened to fully closedpositions, or to any intermediate position, and locked in such positionby means of the bolts 81 and nuts S2.

As indicated schematically in FIG. 4, the outboard suction boxes atleast advantageously may be connected through suitable individualcontrol valves 90, 91 and a common suction header 92 to a suitablesuction source such as the intake of a compressor or blower 93, forexample. For proper suction control a bleeder valve 94 may be providedjust upstream of the suction source.

In accordance with another specific aspect of the invention, novel andimproved pull roll means are provided, most advantageously for use inconjunction with the above-described feed table apparatus, but alsosuitable for use in conjunction with other facilities for the supply ofcorrugated carton blanks from a feed source and their transmission on toa subsequent processing apparatus, such as a folder, for example. Thepull roll facilities of the present invention comprise a pair 4of pullrollers 100, 101 (see FIG. 3) which are positioned adjacent the exit ordischarge end of the feed table generally in line with the plane inwhich corrugated carton blanks are -fed one at a time from the table. Inaccordance with known techniques, the pull rollers 100, 101advantageously are driven in synchronism at a speed which is somewhat inexcess of the speed at which blanks are advanced one at a time by thefeed table. Accordingly, as the leading edge of a blank enters the nipformed by the vertically aligned rollers 100, 101, the blank is grippedand forcibly drawn from the feed table and advanced on to a folder orother apparatus located on the discharge side of the pull roller nip. Byoperating the pull rollers 100, 101 at a slightly higher speed than thefeed table apparatus, a predetermined spacing is introduced betweensuccessive blanks as they are discharged from the pull roller nip, whichis a desirable condition for most processing operations.

In accordance with the invention, means are provided for mounting of therespective pull rollers 100, 101 in such a way as to provide for preciseadjustment of the pull roller nip to receive the various standard ilutesizes of corrugated carton blanks. Further, facilities are provided formaintaining precise parallelism between the upper and lower pullrollers, even when handling offcentered or asymmetrical carton blanks,as is often required of a conventional equipment. In the specificapparatus herein illustrated, the principles of the invention arecarried out by mounting the lower pinch roller 101 in fixed relation tothe machine frame 10, as by means of appropriate fixed bearings 102. Theupper pinch roller 100, on the other hand, is mounted vertically abovethe roller 101, in bearings 103 arranged and guided for verticaladjusting movement in slides 104 carried by the basic frame structure.Screw shafts 105 (FIG. 1) engage the bearings 103 at each side of themachine and are actuated by internally threaded worm wheels 106 drivenby worm gears 107 from a common shaft 10S extending transversely acrossthe machine.

As a significant aspect of the invention, there is provided at each sideof the machine a stepped gauge block 109 (FIG. 3) supported rigidly 'bya slide pedestal 110 for slidable adjusting movement in the direction ofthe gauge steps. A handle 111 is provided for convenience of manualmanipulation of the gauge block. A gauge bar 112 is fixed to the bottomof the lupper pull roller bearing 103 and is generally aligned over thestepped gauge block 109, such that it may be brought to bear on any ofthe gauge steps of the block. If desired, detent means or the like maybe provided, defining discrete index positions for the gauge block 109,in which the individual gauge steps are located directly under the gaugebar 112.

In accordance with the invention, the individual steps of the gaugeblock 109 are arranged such that the highest step, at the righthand sidein FIG. 3, corresponds to the corrugated carton stock of maximumthickness to be accommodated by the machine. Typically, this would besocalled A flute corrugated board. The other gauge steps, in descendingorder from right to left, would correspond to corrugated stockthicknesses designated C flute, B flute, D flute, and E flute, forexample, these being the conventional grades of corrugated carton boardpresently commercially handled in large quantities.

As will be understood, the gauge bars 112 and gauge blocks 109 are sorelated to the diameters of the pinch rollers 100, 101 that, at a givensetting of the gauge blocks 109, the pinch roller nip will be slightlynarrower than the nominal thickness of the carton stock to be handled,such that the blanks are firmly gripped by the pinch rollers. As shownparticularly in FIG. 2, for example, each of the pinch rollersadvantageously is provided with a covering of soft rubber or otherresilient materials, provided across its entire effective surface withalternating annular grooves and lands 113, 114. The arrangement is suchthat, as a corrugated carton blank is advanced into the pinch rollernip, it is gripped resiliently by the respective annular lands 114 ofthe upper and lower pinch rollers, accelerated to the peripheral speedof the pinch rollers, and advanced through the pinch roller nip.Desirably, the dimensions and spacing of the annular grooves and lands113, 114 is such that, when the resilient covering material of theannular lands 114 is deformed by the application of gripping pressure toa corrugated carton blank, at least some of the deformation isaccommodated by sideways or axial deformation of the resilient materialinto the area of the grooves 113. By thus reducing the extent ofcircumferential distortion, more positive and accurate feeding of thecarton blanks is assured.

As one of the important advantageous features of the new pinch rollstructure, the actuating arrangements for the movable upper pinch roller100 is arranged to drive the gauge bars 112 solidly down onto thepreselected steps of the gauge block 109, with a force reliably inexcess of any reaction force applied to the pinch rolls upon entry of acorrugated carton blank into the pinch roll nip. Desirably, theactuating mechanism for raising and lowering the upper pinch roller 100includes essentially nonresilient elements, such as the screw shaft 105,threaded worm wheel 106, etc., which, when screwed down tight againstthe gauge blocks, is free of backlash and relatively non-yielding.However, if there were occasion to utilize pneumatic, hydraulic orspring-loaded means for actuating the pinch rollers toward and away fromeach other, the effective force thereof would be such as to reliably andsubstantially exceed any reaction force resulting from entry of a cartonblank into the nip, so that the gauge bars 112 would be retained solidlyagainst the preselected step of the gauge bars 109. In this respect, itwill be understood that the pinch rollers 100, 101 of a typical machineare of substantial length (e.g., 100 inches) and may at any given timebe handling a carton blank of very small dimensions, which may beentering the pull roller nip along an axis offset from the centerline ofthe machine, either by reason of the initial alignment ofthe blank or byreason of its asymmetrical outline, or both. In such cases, even aslight tilting of the pinch rollers out of parallel relationship, asmight result in a conventional apparatus through backlash in theadjusting means, yielding of resilient supports, etc., may cause theblank to be skewed slightly out of its precise initial alignment. Thiswill, of course, undesirably affect subsequent processing operationssuch as folding and securing, and is particularly undesirable where thesubsequent processing includes the operation of securing the foldedcarton blank by taping. With a carton secured by taping, misalignment ofthe seam will cause the tape to be applied across the seam rather thanalong the seam. Further, if the folded carton tube is not secured inprecisely squared condition, there is no opportunity to correct thecondition in a subsequent squaring operation, as often may be done wherethe carton is secured by gluing, for example.

The feed apparatus of the invention is particularly advantageous overallfor the precise, controlled feeding of corrugated carton blanks one at atime, in accurate alignment, so that subsequent processing operationsmay bel performed in a most expeditious and effective manner. Theequipment of the invention, although incorporating features providingfor full adjustability, to accommodate corrugated carton blanks of allsizes, shapes, and thicknesses, provides for precision of handling andcontrol heretofore unattainable in a universal machine.

One of the significant advantageous features of the feed table apparatusresides in the provision of independently movable, small area suctionboxes, which may be selectively positioned and actuated and may beregulated individually as to suction power, such that suction effort maybe applied to the carton blanks in selected areas where it will achieveoptimum effectiveness, and the overall suction effort is kept at apractical minimum to reduce drag on the blank after it has been engagedby the pull roller. In this respect, it will be understood that the pullrollers desirably advance the blank at a speed greater than that of thesuction belt. Accordingly, excessive suction drag on the blank consumesunnecessary power, causes excessive and unnecessary wear on the machineparts, and, probably of greatest significance, will tend to causemisalignment of the blank, particularly in the case of asymmetrical diecuts and the like.

The new suction box arrangement also includes a large plurality oflongitudinally slidable, relatively narrow closure plates which controlthe longitudinal extent of each of a plurality of longitudinallyelongated suction openings. This enables the suction pattern to conformbetter to odd shaped die cut blanks and also enables avoidance ofexcessive suction loss at the rear of the normal full suction opening,which would be experienced with severely curved blanks. If desired, ofcourse, the slidably adjustable closure plates could be utilized with acontinuous, full-width suction box, for example, being selectivelyopened, controlled, and adjusted for desired suction effects.

The new feed table also includes an advantageous supporting arrangementfor an auxiliary feeder roll arranged to contact and impart a slightforward impetus to the back edge portion of the lowermost blank of astack. The facilities of the present invention include a novel andimproved arrangement for adjustably locating an auxiliary feeding roll,so as to contact the back edge of the blank at a precise location,regardless of the extent of bowing or curvature of the blank or of itsdimensions, within the capacity limits of the machine.

As will be understood, the various inventive features described hereinare most advantageously employed in combination, but are alsosusceptible of separate utilization, as circumstances demand or permit.Likewise, the specific forms of the inventive features hereinillustrated and described are intended to be representative only, ascertain changes may be made therein without departing from the clearteachings of the disclosure. Accordingly, reference should be made tothe following appended claims in determining the full scope of theinvention.

What is claimed is:

1. A vacuum feed table for advancing corrugated carton blanks or thelike, which comprises (a) a table frame,

(b) a perforated belt movably carried -by the table frame and having apredetermined exposed traverse in which the bel-t may be exposed to acorrugated carton blank or the like,

(c) said belt having a predetermined belt width,

(-d) a plurality of suction boxes mounted adjacent the concealed side ofsaid belt over a portion of its exposed traverse,

(e) the plurality of said suction boxes having a total effective widthsignificantly less than said predetermined belt width, and

(f) means for independently adjusting at least certain of said suctionboxes with respect to said perforated belt, whereby to cause suction tobe applied through said belt at preselected limited areas thereof.

2. A vacuum feed table `according to claim 1, further characterized by(a) there being a plurality of at least four suction boxes,

(b) the combined effective suction width of said boxes being less thanhalf the effective suction width of the belt, and

(c) each of said boxes being independently movable relative to saidbelt.

3. A vacuum feed table according to claim 2, further characterized 4by(a) means mounting 'said suction boxes in transverse alignment along anaxis extending across the width of said belt, and

(b) means accessible from the sides of said feed table for effectingtransverse adjustment of said boxes along said axis.

4. A Isuction box, for use in a vacuum feed table for corrugated cartonblanks tand the like and in combination with a perforated feed belt,comprising (a) means forming a lsuction chamber having a suction openingand a suction outlet, and

(b) a plurality of valve plates disposed in side-by-side relationIacross the transverse extent of said suction chamber and lselectivelymovable between open and closed positions, said valve plates forming aflat surface for the partial support of a suction belt or the like.

5. A suction box according to claim 4, further characterized by (a) saidvalve plates being elongated in a longitudinal direction and adjustablelongitudinally to form individual suction chamber openings of variablelongitudinal dimension.

6. A vacuum feed table for advancing corrugated carton blanks or thelike, which comprises (a) a perforated suction belt having apredetermined suction width.

(b) means for supporting and advancing said suction belts through apredetermined exposed traverse in which lthe belt may be exposed to acorrugated carton blank or the like,

(c) a suction box cooperatively related to said belt for applyingsuction to a preselected limited area thereof in the region of saidexposed traverse,

(d) said suction box having an effective suction Width significantlyless than said predetermined suction width in the region of said exposedtraverse, and

(e) means for adjustably positioningy said suction box relative to saidbelt within said region.

7. A vacuum feed table according to claim 6, further including (a)suction box means additional to and separate from said suction boxpositioned for cooperative suction relation with a portion of saidsuction belt in the region of said exposed traverse.

8. A vacuum feed table according to claim 7, further characterized by(a) said suction box means being adjustably movable relative to saidbelt in said region and relative to said suction box.

9. A feed table for advancing corrugated carton blanks from the bottomof a stack, comprising (a) a movable belt having a traverse portioncontacting the forward edge area of a blank,

(b) an auxiliary feeding roll positioned adjacent the rear edge of a`stack of blanks for imparting a forward impetus to a blank,

(c) first means to adjust said auxiliary feeding roll generally inforward and rearward directions, and

(d) second means for adjusting said auxiliary feeding roll verticallyrelative to said traverse portion of the belt.

10. A feed table according to claim 9, further characterized by (a) saidsecond means comprising a pair of pivot arms disposed in straddlingrelation to said belt,

(b) said rst means comprising a roll supporting carriage mounted by saidpivot arms for movement toward and away from the pivot axis thereof.

11. A feed table accordingf to claim 1t), further characterized by (a)said traverse portion of the belt being disposed generally horizontally,for advancing carton blanks in a generally horizontal plane from thebottom of a generally vertical stack of generally horizontally -orientedblanks,

(b) said auxiliary feeding roll being disposed in predeterminedadjustable operating positions generally above the plane of saidtraverse portion.

EDWARD A. SROKA, Primary Examiner.

